In the fifth group of qualitative analysis,$(NH_4)_2CO_3$ is added to precipitate out the carbonates. We do not add $Na_2CO_3$ because

Choose the correct tests with respective observations.
$(A)$ $CuSO_4$ (acidified with acetic acid) $+$ $K_4[Fe(CN)_6]$ $\rightarrow$ Chocolate brown precipitate.
$(B)$ $FeCl_3 + K_4[Fe(CN)_6]$ $\rightarrow$ Prussian blue precipitate.
$(C)$ $ZnCl_2 + K_4[Fe(CN)_6]$,neutralised with $NH_4OH$ $\rightarrow$ White or bluish white precipitate.
$(D)$ $MgCl_2 + K_4[Fe(CN)_6]$ $\rightarrow$ Blue precipitate.
$(E)$ $BaCl_2 + K_4[Fe(CN)_6]$,neutralised with $NaOH$ $\rightarrow$ White precipitate.
Choose the correct answer from the options given below:

The solution of $BiCl_{3}$ in dil. $HCl$ when diluted with water,forms a white precipitate which is:

The reagent that can distinguish between silver and lead salt is

An aqueous solution of an inorganic salt on treatment with $HCl$ gives a white precipitate. This solution contains

Which reagent is used to test for the presence of the $Fe^{+2}$ ion?